Conventionally, scroll compressors have been known which include a compression mechanism having a fixed scroll and an orbiting scroll.
Japanese Patent No. 3731433 discloses this type of scroll compressor, which includes a compression mechanism having a fixed scroll and an orbiting scroll. Specifically, the fixed scroll includes a disc-shaped end plate, a cylindrical outer peripheral wall standing on an edge of the end plate of the fixed scroll, and a scroll wrap standing inside the outer peripheral wall. The orbiting scroll includes an end plate that is in sliding contact with ends of the outer peripheral wall and the wrap of the fixed scroll. The orbiting scroll also includes a wrap standing on the end plate of the orbiting scroll. In the compression mechanism, the scrolls meshing with each other form compression pockets therebetween. The orbiting scroll eccentrically orbiting the fixed scroll gradually decreases the volume of the compression pockets, thereby compressing fluid in the compression pockets.
Such a scroll compressor disadvantageously increases sliding resistance on a contact surface between the fixed scroll and the orbiting scroll. To avoid this problem, the scroll compressor of U.S. Pat. No. 3,731,433 includes an oil groove on a surface, of the outer peripheral wall of the fixed scroll, on which the fixed scroll is in sliding contact with the orbiting scroll. High pressure lubricating oil on the oil groove decreases the sliding resistance on the sliding contact surface.